/* * BIRD -- Neighbor Cache * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #undef LOCAL_DEBUG #include "nest/bird.h" #include "nest/iface.h" #include "nest/protocol.h" #include "lib/resource.h" #define NEIGH_HASH_SIZE 256 static slab *neigh_slab; static list sticky_neigh_list, neigh_hash_table[NEIGH_HASH_SIZE]; static inline unsigned int neigh_hash(struct proto *p, ip_addr *a) { return (p->hash_key ^ ipa_hash(*a)) & (NEIGH_HASH_SIZE-1); } static int if_connected(ip_addr *a, struct iface *i) /* -1=error, 1=match, 0=no match */ { struct ifa *b; if (!(i->flags & IF_UP)) return 0; WALK_LIST(b, i->addrs) { if (ipa_equal(*a, b->ip)) return -1; if (b->flags & IA_UNNUMBERED) { if (ipa_equal(*a, b->opposite)) return 1; } else { if (ipa_in_net(*a, b->prefix, b->pxlen)) { if (ipa_equal(*a, b->prefix) || /* Network address */ ipa_equal(*a, b->brd)) /* Broadcast */ return -1; return 1; } } } return 0; } neighbor * neigh_find(struct proto *p, ip_addr *a, unsigned flags) { neighbor *n; int class; unsigned int h = neigh_hash(p, a); struct iface *i, *j; WALK_LIST(n, neigh_hash_table[h]) /* Search the cache */ if (n->proto == p && ipa_equal(*a, n->addr)) return n; class = ipa_classify(*a); if (class < 0) /* Invalid address */ return NULL; if ((class & IADDR_SCOPE_MASK) < SCOPE_SITE || !(class & IADDR_HOST)) return NULL; /* Bad scope or a somecast */ j = NULL; WALK_LIST(i, iface_list) switch (if_connected(a, i)) { case -1: return NULL; case 1: if (!j) j = i; /* Fall-thru */ } if (!j && !(flags & NEF_STICKY)) return NULL; n = sl_alloc(neigh_slab); n->addr = *a; n->iface = j; if (j) { add_tail(&neigh_hash_table[h], &n->n); add_tail(&j->neighbors, &n->if_n); } else add_tail(&sticky_neigh_list, &n->n); n->proto = p; n->data = NULL; n->aux = 0; n->flags = flags; return n; } void neigh_dump(neighbor *n) { debug("%p %I ", n, n->addr); if (n->iface) debug("%s ", n->iface->name); else debug("[] "); debug("%s %p %08x", n->proto->name, n->data, n->aux); if (n->flags & NEF_STICKY) debug(" STICKY"); debug("\n"); } void neigh_dump_all(void) { neighbor *n; int i; debug("Known neighbors:\n"); WALK_LIST(n, sticky_neigh_list) neigh_dump(n); for(i=0; i<NEIGH_HASH_SIZE; i++) WALK_LIST(n, neigh_hash_table[i]); debug("\n"); } void neigh_if_up(struct iface *i) { neighbor *n, *next; WALK_LIST_DELSAFE(n, next, sticky_neigh_list) if (if_connected(&n->addr, i) > 0) { n->iface = i; add_tail(&i->neighbors, &n->if_n); rem_node(&n->n); add_tail(&neigh_hash_table[neigh_hash(n->proto, &n->addr)], &n->n); DBG("Waking up sticky neighbor %I\n", n->addr); if (n->proto->neigh_notify && n->proto->core_state != FS_FLUSHING) n->proto->neigh_notify(n); } } void neigh_if_down(struct iface *i) { node *x, *y; WALK_LIST_DELSAFE(x, y, i->neighbors) { neighbor *n = SKIP_BACK(neighbor, if_n, x); DBG("Flushing neighbor %I on %s\n", n->addr, i->name); rem_node(&n->if_n); n->iface = NULL; if (n->proto->neigh_notify && n->proto->core_state != FS_FLUSHING) n->proto->neigh_notify(n); rem_node(&n->n); if (n->flags & NEF_STICKY) add_tail(&sticky_neigh_list, &n->n); else sl_free(neigh_slab, n); } } void neigh_prune(void) { neighbor *n; node *m; int i; DBG("Pruning neighbors\n"); for(i=0; i<NEIGH_HASH_SIZE; i++) WALK_LIST_DELSAFE(n, m, neigh_hash_table[i]) if (n->proto->core_state == FS_FLUSHING) { rem_node(&n->n); if (n->iface) rem_node(&n->if_n); sl_free(neigh_slab, n); } } void neigh_init(pool *if_pool) { int i; neigh_slab = sl_new(if_pool, sizeof(neighbor)); init_list(&sticky_neigh_list); for(i=0; i<NEIGH_HASH_SIZE; i++) init_list(&neigh_hash_table[i]); }